Chaga is a fungus with a charcoal-like appearance that grows primarily on the trunks of birch trees. Once Chaga infects a tree trunk, it can grow there for up to 80 years. The mushroom has been used for centuries and is often touted as a cure-all within the realm of alternative medicine: From gastrointestinal diseases to cancer, there are few ailments for which Chaga has not been used as a potential remedy.[1]